This invention relates to hammocks, particularly a hammock having a ridge cord providing a predictable sag in the hammock fabric.
For camping and other recreational activities, different hammocks have been developed to provide shelter from insects, ground dwelling creatures and inclement weather. Being suspended above the ground, hammocks provide a more comfortable, dry, warm and clean surface than do tents.
Existing hammocks are entered by climbing over one side. This is difficult and sometimes dangerous, because the hammock is out of balance when a person enters it. The potential occupant pushes down one of the sides of the hammock, as low as possible, towards is its longitudinal axis of symmetry, to allow his access. As soon as the occupant sits down and his weight comes off his feet, the hammock swings back into its original position, tumbling the occupant backwards, and sometimes out of the hammock.
The entrance in an enclosed hammock, which is usually between the bed and insect net, is normally closed by a zipper. The zipper is tensioned and is easily damaged, if it is not fully opened before entry. If the zipper is damaged the hammock can no longer provide protection from insects. It is known also that a zipper in an enclosed hammock is its most vulnerable feature. In known hammock designs, where each suspending rope is attached to the hammock through a sewn sleeve at each end, all of the occupant""s weight is transmitted to the stitches of the sewn sleeve. If one or several stitches are overloaded, they can fail and the entire stitching can unravel under the weight of the occupant. If the stitching is stronger than the fabric fibers, concentration of tension at one point may cause the material to fail, starting a tear which can open quickly and not stop until the occupant reaches the ground.
Hammock sag until now had to be adjusted by trial and error, by adjusting the suspending ropes while tying them to their anchors. If the suspending ropes at each end of the hammock are attached so that too much slack is present, the resulting sag will also be increased. In this situation, the occupant will be bent, and hence in an uncomfortable position. If the suspending ropes at each end of the hammock are pulled too tightly, the sag will be reduced too much. In this situation, trying to climb into the hammock is difficult and dangerous.
Hammocks of rectangular and trapezoidal shape are known. They allow a relatively restricted movement of occupant""s arms and hands and they do not comply with the requirement that at the middle of the hammock, where the occupant is wider, the hammock must be wider as well. Attempts have been made to address and solve the above existing concerns. But it is apparent that up to the present time, there remains important shortcomings in hammocks.
U.S. Pat. No. 5,038,428 discloses a pillow and a slit added to an otherwise conventional hammock. The pillow is mounted atop the hammock, adjacent to the longitudinal edge mid-length of the hammock, so that the transverse axis of symmetry of hammock bisects the pillow. The incision has a predetermined longitudinal extent and is also positioned mid-length of the hammock and is bisected by the transverse axis of symmetry. The pillow and slit are on opposite sides of the longitudinal axis of symmetry of the hammock. A first individual standing in the incision may massage a second recumbent individual, whose head is supported by the pillow and whose feet may extend below the hammock or may rest atop the hammock on opposite sides of the first individual. The disclosed hammock is not designed for general use, but for a very specific one. The central location of the incision on one side of the longitudinal of symmetry of the hammock, does not allow a proper entry for the occupant.
U.S. Pat. No. 4,686,720 discloses a hammock comprising a lower support which is sewn to an upper cover. The lower support is cut in a trapezoidal shape and the wide part is intended to accommodate occupant""s head and shoulder, the narrow lateral end being slightly gathered. A strip of fabric is sewn to the gathered fabric. The strip as well as the material of the lower fabric support, at the wide end, is folded over twice, sewn down and grommets are placed at intervals in the folded strip. A shortcoming of this hammock is that the trapezoidal form of the lower support does give the occupant a sense of space in the middle of the hammock and restricts movement of his arms and hands.
U.S. Pat. No. 4,001,902 discloses a combination comprising a hammock, an insulated sleeping bag and a tent. The hammock consists of a cloth of rectangular shape with a pocket, loop or similar device at each end, to accommodate a spreader bar of rigid material, such as wood or flight metal. Attached at two or more points to each spreader bar is a stringing assembly of approximately 4xe2x80x2 to 5xe2x80x2 in length which leads to a single point, such as a metal ring, which, in turn, is attached by a rope to a tree. The tent is held in position over the hammock and sleeping bag by a separate ridge cord attached to the same trees. As can be seen, the manner of attaching the combination bed and shelter, by using a pocket or loop at the end of the hammock, a spreader bar and a stringing assembly, is complicated.
The present invention is directed, broadly, to a hammock which includes a bed having an entrance slit, situated in the same vertical plane as its longitudinal axis of symmetry and located on one side of its center of symmetry.
The bed includes as well a self-closing feature for the entrance slit, located at midpoint of its short side, where the entrance slit begins.
This bed is formed from a rectangular sheet of material whose short ends are folded into a bundle. Each bundle of gathered folds is used to fasten the hammock by suspending ropes to anchors such as trees.
A ridge cord is provided for adjusting the sag of the hammock. The ridge cord extends in a vertical plane of symmetry, and goes through each opposite bundle of gathered folds, where it is connected to each suspending rope.
A side adjustment cord of the rectangular sheet has one end attached to the middle of each longitudinal side of the rectangular sheet, the other end being fastened to a fixed element, one side adjustment cord being provided at each side of the hammock.
The hammock has a lozenge shape as viewed from the top. This shape is formed when opposite side adjustment cords are outwardly stretched and opposite suspending ropes are tensioned. This bed is provided with a canopy cut in a lozenge form from a sheet of material. At each side of the canopy, where two concurrent edges of the lozenge form intersect the transversal axis of symmetry, an adjustably extending cord is attached.
In one aspect of this invention, the hammock has a bed which includes an entrance slit, situated in the same vertical plane as its longitudinal axis of symmetry and located on one side of its center of symmetry. The entrance slit extends from one of the short sides of the rectangular sheet of the flexible material from which it is made to a point short of its center of symmetry. The above disclosed bed of this hammock comprises as well a self- closing feature which is obtained by folding together several times, and then, holding in place, the edges of the entrance slit close to the corresponding short side of the substantially rectangular sheet of material, where the slit extends.
In another aspect of the invention, the hammock has a bed including a number of to gathered folds, situated at both of its ends and made of each short side of a substantially rectangular sheet which forms the bed. The bundle of gathered folds is used to fasten the hammock by suspending ropes to anchors. The bundle of gathered folds is made of each short side of the substantially regular sheet, which short side is folded several times parallel to the longitudinal axis of the rectangular sheet. The first fold is made towards the longitudinal axis and consists essentially of two layers, followed by a second fold of four layers, then eight layers and, finally, sixteen layers. Two resulting bundles of sixteen layers are folded together to form one bundle of gathered folds of thirty two layers of material, which are fastened together permanently, and in which one or more holes for suspending ropes are made. An accordion type of folding is an alternative solution. The folds of this accordion type of folding are fastened permanently and provided with one or more holes for attaching suspending ropes In another aspect of the invention, the hammock comprises a bed which includes for adjusting its sag, a ridge cord extending in a vertical plane, which plane includes the hammock""s longitudinal axis of symmetry and going to the hammock ends, where is adapted to be attached individually to suspending ropes.
Another aspect of the invention is that the hammock has a ridge cord extending in a vertical plane, which plane includes the hammock""s longitudinal axis of symmetry and, after passing through each of the hammock""s ends, to which it is fastened, continues as a suspending rope.
This ridge cord has an adjustable length for altering its sag, according to individual comfort requirements. The adjustment is obtained by untying one end of the ridge cord and retying again to a shorter or longer length. Alternatively, an adjustment device may be used in combination with a part of the ridge cord which is intended as a slacked portion. This part is unwrapped or wrapped accordingly around the sag adjustment device, when the ridge cord is not under tension. This way, the extension of the slacked portion and consequently, the resulting number of subtracted or added wraps determines the workable length of the ridge cord, which effectively adjust the comfort level of the hammock.
In another aspect of this invention, the hammock comprises a bed including a side adjustment cord attached at one end to the middle of each longitudinal side of a substantially rectangular sheet from one which the bed is made, the other end being fastened to a fixed element. The adjustment cord is provided at each side of the hammock.
This hammock has a lozenge shape, viewed from the top, formed when opposite side adjustment cords are outwardly stretched and opposite suspending ropes of the hammock are tensioned. In another aspect of this invention, the hammock comprises a bed which includes a canopy made in a lozenge form from a sheet of substantially synthetic material, to which canopy an adjustably extending cord is attached with one end where two concurrent edges of the lozenge intersect the transverse axis of the sheet from which the canopy is made. The other end of the adjustably extendible cord is joined to a fixed feature. Each two concurrent edges of the lozenge form sheet, at their point of intersection with the longitudinal axis of the sheet, is attached to a suspending rope of the hammock.